Device to form chain links of various shapes from round wire

ABSTRACT

A chain making machine having a split bending mandrel consisting of a leverage-driven movable part and a stationary part engaging each other in a plane for joining which is disposed somewhat higher then the axis of symmetry of the link in order to completely rule out flash formation in the plane of symmetry of the link. The leverage provides for rigid engagement of the two parts of the mandrel, thus precluding flash formation in the plane of their joint.

United States Patent [1 1 Trofimov et al.

[ 1 Sept. 18, 1973 DEVICE TO FORM CHAIN LINKS OF VARIOUS SHAPES FROM ROUND WIRE [76] Inventors: Igor Dmitrievich Troiimov,

Filed:

Mosfilmovskaya ulitsa 25, kv. 78; Jury Mikhailovich Korobeinikov, Deguninskaya ulitsa, 12, kv. 5; Vadim Alexandrovich Pavlov, Kropotkinskaya ulitsa, 40, kv. 15, all of Moscow; Jury Mikhailovich Smirnov, Ploschad 111 lnternatsionala, l1, kv. 6, Azov; Lev Nikolaevich Shevyakov, deceased, late of Pestavsky pereulok, 6, kv. 5, Moscow; by Vera Stepanovna Shevyakova, Pestovsky pereulok, 6, kv. 5, Moscow; Natalya Lvovnav Tiskovieh, Petovsky pereulok, 6, kv. 5, Moscow; Klavdia Andreevna Shevyakova, ulitsa Kuusinena, l7, kv. 126, Moscow, all of USSR. administrators Mar. 30, 1972 Appl. No.: 239,623

US. Cl. 59/27 Int. Cl B211 1/02 Field of Search 59/27, 23, 18, 22, 59/24, 25

[56] References Cited UNITED STATES PATENTS 65,132 5/1867 Stever 59/23 427,458 5/1890 59/18 1,438,474 12/1922 59/23 1,244,448 10/1917 59/23 3,431,723 3/1969 Wattler 59/27 FOREIGN PATENTS OR APPLlCATlONS 696,445 10/1930 France 59/22 654,664 11/1928 France 59/18 Primary Examiner-Charles W. Lanham Assistant Examiner-Gene P. Crosby Attorney-Holrnan and Stern [57] ABSTRACT A chain making machine having a split bending mandrel consisting of a leverage-driven movable part and a stationary part engaging each other in a plane for joining which is disposed somewhat higher then the axis of symmetry of the link in order to completely rule out flash formation in the plane of symmetry of the link. The leverage provides for rigid engagement of the two parts of the mandrel, thus precluding flash formation in the plane of their joint.

2 Claims, 5 Drawing Figures Patented Sept. 18, 1973 3,759,034

3 Sheets-Sheet 1 Patented Se t. 18, 1973 3 Shuts-Sheet 2 FIG. 4

Patented Sept. 18, 1973 3,759,034

3 Shanta-Shoot 1' DEVICE TO FORM CHAIN LINKS OF VARIOUS SHAPES FROM ROUND WIRE The present invention relates to chain making equipment, and is used in the cold manufacture of one-joint chain links and their binding into a chain.

Chain bending machines are known which are designed to form chain links of various shapes, said machines comprising a split bending mandrel which consists of movable and stationary parts whose ends are engaged in a plane whose joint is perpendicular to the mandrel axis. A profiled groove is made on those parts of the mandrel on either side of said plane of joint, which is the zone of forming the product, and which determines the internal configuration of the formed product. In the conventional devices, the plane of joint of the bending mandrel passes through the axis of symmetry of the profiled groove. The cross section of the profiled groove on the both parts of the bedning mandrel has a radius being not less than that of the cross section of the product.

In the conventional device, the movable part of the mandrel is driven by a cam through a leverage system which at the time of forming the link is deformed by the axial loads, thus causing disconnection of the parts of the mandrel, and hence, formation of a clearance between these parts, whereinto flows the metal of the link to be formed, with a shaped circular flash being thus formed on its inner surface.

Besides that, the formation of the flash which reduces the link accuracy irregardless of the rigidity of the drive system is also aided by the joint of the two parts of the mandrel lying in the plane of symmetry of the product.

During the chain making operation, the flash on each link is gradually crushed by axial forces, which changes the specified pitch of the chain causing its early failure.

During the employment of the conventional device in a chain bending machine, the product after being formed on the bending mandrel, is removed therefrom. For this purpose the movable part of the bending mandrel together with the product disposed in the plane of joint withdraws from the stationary part of the bending mandrel.

In the process of disengagement of the mandrel parts the product may stick to the stationary part, or it may be wrongly oriented on the movable part. Besides, the product may come off the movable part of the mandrel.

To preclude such situations, a stripping mechanism is employed in chain bending machines which complicates the design of the machine, and reduces its capacity factor.

It is the object of the present invention to provide a device that would secure production of chain links having higher accuracy and qualityv through the elimination of the flash on the inner surface of the link in its plane of symmetry.

Proposed herein is a device for forming chain links of various shapes from round wire, comprising a split bending mandrel, which consists of a leverage-driven movable part and a stationary part engaging each other in a plane of joint which is perpendicular to the mandrel axis, and a profiled groove made on said parts of the mandrel on either side of their plane of joint within the link forming zone, said groove defining the internal configuration of the link to be formed. According to the invention, the profiled groove on the stationary part of the mandrel'has in its cross-section a radium which is not less than that of the link cross-section, while the cross-section of the profiled groove made on the movable part of the mandrel consists of a portion whose radius is not less than the radius of the link cross-section, and a portion conjugate therewith and constituting a straight-line generatrix perpendicular to the plane of joint, the length of which straight-line generatrix can be up to 30 percent of the diameter of the link crosssection, and said leverage system providing for rigid engagement of the two parts of the mandrel, thus preventing the formation of a flash on the link in the plane of their joint.

The leverage system should advantageously comprise three levers, two of which are hinged to the movable part of the bending mandrel and to a fixed base, respectively, while the third lever one end of which is seated on the same axle as said two levers, and which has its second end connected with a cam through an additional lever.

In the proposed device, the plane of joint of the two parts of the bending mandrel passes above the plane of symmetry of the link, thus completely ruling out flash formation in the plane of symmetryof the link, and thereby raising the accuracy of the process as a whole.

The drive for the movable part of the mandrel comprises a leverage system that secures the rigid engagement of the two mandrel parts, and also helps to prevent flash formation at the plane of joint.

Since the plane of joint of the parts of the bending mandrel is disposed above the plane of symmetry of the link, the contact area of the link with the movable part of the profiled groove on the mandrel becomes greater than its contact area with the stationary part of the profiled groove.

As a result, when the movable part of the mandrel withdraws from the stationary part, the link always remains thereon. This obviates the need for using a stripping mechanism in the chain bending machine, thus simplifying the design of the latterand increasing its production capacity.

For a better appreciation of the idea of the invention the following drawings of the detailed description thereof are presented, wherein:

FIG. 1 is a sectionalized general view of the device for forming chain links;

FIG. 2 shows the parts of the split bending mandrel in the link forming zone at the moment of its formation;

FIG. 3 shows the parts of the split bending mandrel in the link forming zone at the moment of its removal;

FIG. 4 is a side view of the split bending mandrel in the link forming zone;

FIG. 5 is a schematic diagram of the chain bending machine comprising the present device.

GENERAL DESCRIPTION OF THE DESIGN AND DETAILED DESCRIPTION OF THE UNITS The device for forming chain links comprises a split bending mandrel 1 (FIG. 1) which consists of a movable part 2 and a stationary part 3.

The stationary part 3 (FIG. 4) of the bending mandrel l is mounted in a slot in bed 4, and is rigidly attached thereto by a screw 5 through a nut 6 which serves for the initial adjustment of the stationary part 3 of the bending mandrel 1 with respect to its movable part 2.

The movable part 2 of the bending mandrel 1 is capable of traversing in guides 7 made in housing 8 (FIG. 1), and is driven by a leverage device 9.

The movable part 2 and the stationary part 3 of the bending mandrel 1 engage each other in a plane at joint 10 (FIG. 2) which is perpendicular to the axis of the mandrel, and forms the line 11 in the shaping zone on parts 2, and 3 of the mandrel 1 on either side of the plane at joint 10. A profiled groove 12 which, in the process of bending, defines the internal configuration of link 1 1.

Section 13 of the profiled groove 12 (FIG. 3) located on the stationary part 3 of the bending mandrel 1 has a cross section radius of not less than that of the crosssection of the link.

The section of the profiled groove 12 located on the movable part 2 of mandrel 1 consists of two portions, one of which, 14 (FIG. 3), has a radius of not less than that of the cross-section of product 11, while the second portion, 15, conjugate therewith, constitutes a straight-line generatrix perpendicular to the plane of joint 10.

The length of the straight-line generatrix 15 is up to 30 percent of that of the diameter of the link crosssection.

Leverage device 9 (FIG. 1) driving the movable part 2 of mandrel 1 consists of three levers, one of which, lever 16, is hinged to a fixed base 17, and the second lever, lever 18, is hinged to the movable part 2 of the bending mandrel 1.

Levers 16 and 18 are seated on one a axle 19 with the end of the third lever 20, whose other end is connected through a lever 21 which is connected with a cam 22.

OPERATION OF THE DEVICE Feed rollers 23 (FIG. 5) driven from a cam 24, which is mounted on a cam shaft 25, through a linkage system 26 and a feed box 27 which pull wire 28 through straightening rollers 29 into an immovable cutting-off bushing 30 and a movable cutting-off bushing (not shown) secured on a slide 31, up to a fixed stop 32.

As slide 31 moves forward, the movable and immovable bushings cut off a gauge blank equaling the evolved length of link 11 (FIG. 2), and when slide 31 moves back (FIG. 5) the blank of link 11 is transposed to the centre line of a pusher 33. Pusher 33 advances the blank of link 11 into the working zone 34 for the shaping of the link, wherein the blank is pressed by the clamps (not shown) of slide 35 to the straight-line portion of the profiled groove 12 (FIG. 2) of the bending mandrel 1.

The forward movement of the bending slides 31 and 36 (FIG. 5) having forming rollers 37 mounted thereon bend the ends of the blank of link 11 about mandrel 1 to about 90. Then slide 31 with one of rollers 37 stops, and slide 36 with the other forming roller 37 finishes bending the other end of the blank of link 11 and then retracts to its initial position.

The stoppage of slide 31 is necessary for the next feed cycle of wire 28.

At the end of the next feed cycle of wire 28 as described above, slide 31 continuing to move ahead cuts off the next blank from the fed wire 28, and at the same time its forming roller 37 completes the bending of the second end of the blank of link 11 about mandrel 1, thus ending the shaping of link 11.

Thereupon slide 31 retracts to its initial rear position.

The clamps (not shown) of slide 35, which retain the blank in the profiled groove 12 during the forming of link 11, retract to their initial position at the end of the forming process, so as to enable the link to be tilted to The effect of cam 22 (FIGS. 1, 5) and lever 21 on lever 20 moves it leftwards to sink lever 18 hinged to the movable part 2 of the bending mandrel 1.

As a result, the movable part 2 of the bending mandrel lowers together with the product link 1 l displacing it from plane 38 (FIGS. 2, 3) of bending link 11 to plane 39 for its removal from the movable part of the bending mandrel.

Grips 40 (FIG. 3) of the mechanism of a tilter 41 (FIG. 5), which are at this moment disposed in the horizontal plane, approach link 11 sunk together with the movable part 2 of the bending mandrel l, and engage it. Now the movable part 2 of the bending mandrel 1 sinks to its lowermost position, and grips 40 by means of tilter 41 and turns the link to 90.

As soon as link 11 tilts to 90, lever 20 (FIG. 1) under the action of cam 22 and lever 21 moves to the right, thus lifting lever 18 hinged to the movable part 2 of mandrel l, and engaging it with the stationary part 3 in the plane of joint 10 (FIG. 2).

At the time of the engagement of the two parts of the mandrel, the position of levers 18 and 16 (FIG. 1) is secured, at which the angle of their deviation from the vertical is less than the angle of friction in the hinges of levers 16, 18, and 20.

The tilted link 11 while being held in grips 40 (FIG. 3), pusher 33 (FIG. 5) forces thereinto the freshly cut off blank of the next thereinto.

Thereupon the clamps of slide 35 press the new blank to the straight-line portion of the profiled groove 12, where the link bending cycle is resumed. A chain is thus formed.

What we 'claim is:

l. A device for forming chain links of various shapes from round wire, comprising: a split bending mandrel consisting of movable and stationary parts engaging each other in a plane of joint perpendicular to the axis of the mandrel; a profiled groove defining the internal configuration of the product, which groove is made on said parts of said mandrel within a link forming zone on either side of the plane of joint, one section of said profiled groove being located on said stationary part of the mandrel and having in its cross-section a radius not less than that of the cross-section of the product, and the other section of said profiled groove being located on said movable part of the mandrel, and consisting of a portion whose radius is also not less than the radius of the cross-section of the product, and a portion conjugate therewith and constituting a straight-line generatrix perpendicular to the plane of joint, the length of which'generatrix can be up to 30 percent of the diameter of the product cross-section; a leverage system to drive said movable part of the bending mandrel, which provides for the rigid engagement of the two parts of the mandrel, and thus precluding flash formation on the product in the plane of their joint.

2. A device as claimed in claim 1, wherein the leverage system comprises three levers, two of which are hinged to the movable part of the bending mandrel and to'a fixed base, respectively, while the third lever whose end is seated on one axle with said two levers, has its other end connected with a cam through an additional lever.

is a 4: a- 4: 

1. A device for forming chain links of various shapes from round wire, comprising: a split bending mandrel consisting of movable and stationary parts engaging each other in a plane of joint perpendicular to the axis of the mandrel; a profiled groove defining the internal configuration of the product, which groove is made on said parts of said mandrel within a link forming zone on either side of the plane of joint, one section of said profiled groove being located on said stationary part of the mandrel and having in its cross-section a radius not less than that of the cross-section of the product, and the other section of said profiled groove being located on said movable part of the mandrel, and consisting of a portion whose radius is also not less than the radius of the cross-section of the product, and a portion conjugate therewith and constituting a straight-line generatrix perpendicular to the plane of joint, the length of which generatrix can be up to 30 percent of the diameter of the product cross-section; a leverage system to drive said movable part of the bending mandrel, which provides for the rigid engagement of the two parts of the mandrel, and thus precluding flash formation on the product in the plane of their joint.
 2. A device as claimed in claim 1, wherein the leverage system comprises three levers, two of which are hinged to the movable part of the bending mandrel and to a fixed base, respectively, while the third lever whose end is seated on one axle with said two levers, has its other end connected with a cam through an additional lever. 